Using radio waves for more efficient solar power

Using radio waves to efficiently convert solar power — that’s the idea behind startup Array Converter, which spoke for one of the first times this week at the AlwaysOn GoingGreen conference in San Francisco. Array Converter has developed solar power conversion electronics — which are used to convert the solar power made from the panels (direct current) into power that can flow on the grid (alternating current) — using a radio wave technology called amplitude modulation.

Array Converter CEO Wendy Arienzo said at the conference: “Marconi came up with radio and called it amplitude modulation. We are taking a well established technology and applying it to solar.”

Asked about Array Converter’s technology after her panel, Arienzo declined to say more about the company’s research, but said the company plans to make an announcement at the Solar Power International conference next month.

Amplitude modulation involves using radio wave to send information — the technology adjusts the amplitude of the radio wave rather than the frequency (FM) — and Array Converter’s work seems to focus on using pulse amplitude modulation. Pulse amplitude modulation is used in Ethernet equipment and for controlling LED lighting. Eric Wesoff at Greentech Media wrote about the company earlier this year, and patent attorney Eric Lane wrote about the startup’s patents in a blog post.

Array Converter is setting out to develop power electronics that are indeed different than the ones commonly used today to convert DC from solar panels to AC in order to be used on site or feed the grid. Solar systems today use inverters to do the power conversion; the inverter gets its name because its design reverses a conversion process to turn AC to DC (this device is called rectifier).

Although Array Converter hasn’t announced products, its website indicates that the company is working on a modulator and controller. And, yes, the startup promises to deliver power electronics that can reduce the overall equipment and installation costs.

Inverters have been used in solar energy systems for decades. Each inverter is typically responsible for about a dozen solar panels. In recent years, some inverter developers have come up with what’s called a microinverter that is paired with each panel.

The use of microinverter has led to the name “AC panel,” because the DC-to-AC conversion now takes place at the panel rather than at a central inverter that sits in a stand-alone box next to the solar array. Array Converter, incidentally, also calls solar panels that use its devices “AC panels.”

All of these technologies are working on improving the efficiency of converting the electric current – power losses are typical during power conversion. A Google-backed startup, Transphorm, is working on reducing that power loss by using a novel material called gallium nitride.